<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        td{
            width: 30px;
            height: 30px;
            line-height: 30px;
            text-align: center;
        }
    </style>
</head>
<body>
    <table border="1" style="border-collapse: collapse;">
        <tr>
            <td colspan="12">1</td>
            <td rowspan="12">2</td>
        </tr>
        <tr>
            <td rowspan="12">4</td>
            <td colspan="10">5</td>
            <td rowspan="10">6</td>
        </tr>
        <tr>
            <td rowspan="10">8</td>
            <td colspan="8">9</td>
            <td rowspan="8">10</td>
        </tr>
        <tr>
            <td rowspan="8">12</td>
            <td colspan="6">13</td>
            <td rowspan="6">14</td>
        </tr>
        <tr>
            <td rowspan="6">16</td>
            <td colspan="4">17</td>
            <td rowspan="4">18</td>
        </tr>
        <tr>
            <td rowspan="4">20</td>
            <td colspan="2">21</td>
            <td rowspan="2">22</td>
        </tr>
        <tr>
            <td rowspan="2">24</td>
            <td colspan="1">25</td>
        </tr>
        <tr>
            <td colspan="2">23</td>
        </tr>
        <tr>
            <td colspan="4">19</td>
        </tr>
        <tr>
            <td colspan="6">15</td>
        </tr>
        <tr>
            <td colspan="8">11</td>
        </tr>
        <tr>
            <td colspan="10">7</td>
        </tr>
        <tr>
            <td colspan="12">3</td>
        </tr>
    </table>
</body>
</html>